I think the Blender source code could be more modulated so that updates are easier. Maya for example separates the subdiv code and the nurbs code into dynamic libraries. To compile Blender, more than 600 source code files have to compile together. Whereas if the components were separate, people could update separate modules and then a Blender update is easier. Similarly, a C-based plugin architecture would make updates easier but those things would require a great deal of work. I don’t want to see it reach a stage where the code becomes unmanageable and with few developers and over 500,000 lines of code, that is a possibility.
However, it’s easy to say things like ‘make it faster’, ‘make it more streamlined’ as if somehow those statements contain magical powers that actually make it happen. The Blender developers know what they are doing and make Blender as good as they can so I don’t think these ambiguous threads really help in any way. If you’d said make Blender more streamlined by moving some parts of the code here and there or removing redundancy then it might be interesting but in that case more suitable for the blender.org site.